Askja

At the end of Route F88 in the heart of the dismal Ódáðahraun, Askja is an 8km-wide volcanic depression, formed from a collapsed subterranean magma chamber. In the centre is a 217m-deep lake, Öskuvatn, its steel-grey waters doing nothing to brighten the setting amongst a colossal lavafield which drained out of Askja in prehistoric times. More recent events have included the appalling eruption at Viti in 1875, and another big outflow of lava in the 1960s, which you traverse en route to the caldera’s rim.